How to delete photos from iPhone while keeping them in iCloud and re-syncing later?

Step 1: Turn Off iCloud Photos on Your iPhone

• Go to: Settings > [your name] > iCloud > Photos
• Toggle off iCloud Photos
• It will ask:
  • “Remove photos from iPhone?” or
  • “Download Photos & Videos”?

If you choose “Remove from iPhone”, photos that are only in iCloud will be removed from the phone.

If you choose “Download Photos & Videos”, it will try to keep a copy of everything on the phone before turning off iCloud Photos (which may fill up your storage). To keep them only in iCloud, choose “Remove from iPhone”.

Step 2: Delete Photos from iPhone (While iCloud Photos Is OFF)

Now, deleting photos only deletes them locally, not from iCloud — because the phone is no longer syncing to iCloud Photos.

That means:

• iCloud Photos remains untouched.
• Only the photos on your phone are removed.

Step 3: Turn iCloud Photos Back ON Later

When you re-enable iCloud Photos:

• Your phone will reconnect to iCloud and attempt to sync with it again.
• Unless storage is full or "Optimize iPhone Storage" is enabled, your device will begin downloading thumbnails/previews of photos stored in iCloud Photos.

But here's the key:

Will it re-download everything to your phone?

• No, not in full, if you use:
• Optimize iPhone Storage (Settings > Photos > Optimize iPhone Storage)
  • This saves storage: only lightweight previews are downloaded unless you open a photo.
• Yes, partially, if you use:
• Download and Keep Originals
  • This downloads the entire full-resolution library, which uses a lot of space.